The invention discloses a ship-borne aircraft tether load calculation method based on a catenary model, which comprises the following steps: simplifying an aircraft model, equivalently taking an aircraft wheel as a spring model, equivalently taking an aircraft fuselage as a rigid body, and equivalently taking a deck as a rigid body; according to the simplified aircraft model, the displacement typeof rigid body structure being determined; by coordinate transformation, the displacement of any point on the rigid body being expressed as the combination of the deformation displacement of the aircraft wheel and the sliding displacement of the rigid body in the plane of the deck; simplifying the tethered rigging model, and constructing the catenary mechanics model of the tethered rigging according to the stress characteristics of the tethered rigging in the relaxed state; taking the force balance of tethered cable as the constraint condition, the simultaneous equations of tethered cable loadbeing constructed and solved by Newton-Raphael method through numerical iteration, and the tethered cable load being obtained. The method for calculating the mooring load of a ship-borne aircraft based on the catenary model provided by the invention can realize fast and accurate calculation of the mooring load of the ship-borne aircraft.